What is Culinary Stagnation?

Why do we still cook as we did in the Middle Ages, with whisks, fire, and saucepans? Why this outdated behavior; when, at the same time, humanity is sending probes to the outer limits of the solar system? Why do our recipes hardly differ from those found in the Viandier….who lived in the 14th century and whose recipes hardly differ from those in Apicius’s De re coquinara. a collection of texts between the 4th and 5th century AD? Why this noticeable technical stagnation?